Update dd-apm-test-agent to 1.18.0 (current release) (#4004)

Co-authored-by: Oleg Pudeyev <[email protected]>

Author: p-datadog

Diff for: .circleci/config.yml

@@ -107,7 +107,7 @@ test_containers:
     image: memcached:1.5-alpine
   - &memcached_port 11211
   - &container_testagent
-    image: ghcr.io/datadog/dd-apm-test-agent/ddapm-test-agent:v1.12.0
+    image: ghcr.io/datadog/dd-apm-test-agent/ddapm-test-agent:v1.18.0
     name: testagent
     environment:
       - LOG_LEVEL=DEBUG

Diff for: docker-compose.yml

@@ -203,7 +203,7 @@ services:
       - ddagent_var_run:/var/run/datadog
 
   testagent:
-    image: ghcr.io/datadog/dd-apm-test-agent/ddapm-test-agent:v1.12.0
+    image: ghcr.io/datadog/dd-apm-test-agent/ddapm-test-agent:v1.18.0
     ports:
         - "127.0.0.1:${DD_TRACE_AGENT_PORT}:9126"
     depends_on: